Gas sockets serve to facilitate the connection between gas pipes fixed inside buildings and a gas-operated appliance, such as a kitchen range or a drier. Using such receptacles allows any gas consumer to get connected to the gas pipe by simple means.
Gas sockets of the above mentioned kind are well known. DE 11 36 294, for example describes a so-called gas connector cock in which connection is made by inserting an appropriate gas hose connector into the connector bore at the tap cock that comprises a cock casing which houses a moveable plug. When turning the gas hose connector the gas connector cock at the same time is put in on, or off position.
In this solution there is the disadvantage that the connector bore, and in particular as regards the sealing ring sitting inside that bore, is not tamper-proof. Also, there is no protection against the ingress of foreign matter. An additional disadvantage is that if no gas hose connector is plugged in the elastic sealing ring is exposed to the light which in turn can make the material to become brittle. As a consequence of such brittleness, tightness of gas connection is no longer guaranteed. A flush mounted installation, as often desired for aesthetic reasons, is possible but entails a high expenditure of work. In addition, manufacturing is highly expensive as the cone-shaped outer surface of the moveable plug and the cone-shaped inner surface of the casing must match perfectly in order to make it gas-tight as required.
From DE 14 29 084 there is known a gas socket the casing of which houses a shut-off valve that is actuated through the gas hose connector. Said shut-off valve comprises a valve seat that can rotate and move in axial direction inside the casing towards which it is sealed off at its outer surface, and a valve disk formed at that end of a shut-off device that faces toward the gas socket's interior, and that cannot be rotated but moved inside the casing in axial direction against the reseat action of a spring.
Also, this gas socket has the same disadvantage as described herein above, i.e. it is not tamper-proof. This design specifically allows intruding foreign matter to move the valve disk against the reseat action of the spring away from its valve seat, and gas will possibly leak out as a consequence. Also, the disadvantage here is that if no gas hose connector is plugged in the elastic sealing is exposed to the light which in turn can make the material to become brittle, with the same consequences as already described herein above. Also this device is not designed for a flush mounted installation.
Another type of gas socket, that also has proved to be reliable in practice, is described in DE 35 19 933 A1. Here, the gas socket is equipped with tube-shaped gas forward body, that can be adjusted by turning inside the casing, to take up a gas connector plug, and an intake port that is arranged at a right angle to the gas forward body. The shut-off device comprises a ball that can turn on the gas forward body's longitudinal axis, and an rectangular port inside that ball. The gas forward body's intake end, which is coupled to the ball to rotate in the same way, protrudes into the ball port's outlet end. The ball's surface rests on two elastic sealing rings that are located diametrical on the casing's walls, seen in longitudinal direction of the intake port. One of theses sealing rings is attached at a tube socket that is inserted in the intake port and serves to press the sealing ring against the ball.
The disadvantage even in this solution is that the connector bore hole is not tamper-proof, in particular as regards the sealing ring inside that hole. Also, foreign matter is not prevented from ingress, and the sealing ring is not protected against exposure to light. An additional disadvantage is the fact that the inserted tube socket requires an extra sealing joint, with a rather high extra expenditure of work. Flush mounting is not possible with this device, too.
In contrast to the above, the solution described in DE 91 12 208 U1 is a gas socket the design of which is the same as already described, in particular in DE 35 19 933 A1, but is specifically designed for use in concealed installations. For this purpose, the casing has a threaded intake socket for a screw connection with coupling ring and can be installed in, and removed from a box designed for flush mounting. The opening to house the gas connector plug is provided in the removable front cover of the box. Also, a nozzle is provided in one of the side walls of the box. The nozzle's end protruding outside the box can be connected to the gas pipe whereat the nozzle's end inside the box is equipped with the coupling ring that can be connected to the intake socket.
Apart from its usability in flush mounted installations, this gas socket comes with the same disadvantages as known from the device described in DE 35 19 933 A1. Also known are plug-in couplings of all sorts that cover up the outlet socket's connector opening when the gas connector plug is removed. Especially use of flaps is found in various variants.
For instance, the printed patent specification DE 253 698 uses a rotatable flap to shut the opening provided in the bonnet; the rotatable flap can be brought in open or closed position by an attached lever that sideways protrudes from the bonnet. In DE 26 23 934 B2, a tilting flap is used to cover the opening, whereat use of a spring-type flap is known from the printed patent specification U.S. Pat. No. 3,931,829. All these devices have in common that their covers do not have any locking device.
DE-AS 15 29 035 describes a plug-in-coupling in which the intake opening is shut by ring segments. The ring segments are fixed in such a way that when turning the shutter ring these segments are tilted away, and make the intake opening accessible. Additionally, the shutter ring is hold in closed position by a latching device that can be released only by means of a key.
The disadvantageous feature in this solution is that the latching device must be separately actuated, that is to say the intake opening can be made accessible without using the appropriate gas connector plug.
The invention is based on the problem of developing a gas socket of the mentioned kind that allows a gas connector plug to get quickly connected and disconnected. When no gas connector plug is connected the gas socket should be tamper-proof and offer protection against the ingress of foreign matter. Also, the gas socket should be fit for concealed installation. According to the present invention, the problem is solved by providing the gas socket with a bonnet that shuts the connector opening at the outlet socket by means of a cover when the gas connector plug is disconnected, with such cover being equipped with a latching device. The latching device is brought into a state ready for unlatching by a first attempt to insert the gas connector plug, to which the cover is adjusted, into an uptake opening. At least one additional move of the gas connector plug is needed to make the connector opening of the outlet socket accessible for the gas connector plug to get connected.
This solution, therefore, constitutes an approach that removes the disadvantages of the prior art as described above. By its latching device, the gas socket is safely protected against tampering. Also, the ingress of foreign matter is prevented.
Other advantageous arrangements of the invention can be found in the other patent claims. It proved especially advantageous to form the latching device from two or more blocking elements that are acting independently from each other. Preferably, such blocking elements should be provided in a single-piece design in which each of them are attached to the cover.
Placing the elastic sealing elements, which are necessary to make the device gastight towards the environment, onto the outlet socket makes sure that the cover offers an absolute protection to said elements from being exposed to light, which in turn avoids the possible risk of embrittlement and, as a consequence, gas leaking from the device.
It proved extremely advantageous in the manufacturing process if the cover was formed be a slider that can move vertically to the outlet socket's axis, with the axes of intake opening, which is formed by bonnet and cover, and outlet socket being staggered.
In another advantageous arrangement, the latching mechanism has at least one blocking element, consisting of one spring leg attached to the slider, where the leg's end is in form of a catch hook, and a holding device provided in a single-piece design that is connected to the bonnet and serves to lock the catch hook into place. By an additional protrusion provided on the external side of each leg together with a limit stop inside the bonnet, that serves to delimit the protrusion's motion when the leg moves against the reseat action of the spring, the latching device is effectively prevented from being unlatched if the acting forces are outside of the action points where they should be when inserting the gas connector plug, as it may be in case of attempted tampering.
In other slightly changed design versions, the cover forming slider can move in an angle to the outlet socket's axis, or the cover is formed by two or more flaps, instead of a slider.